I second using a can. That will probably allow you to get at least one more shot off before they turn on the afterburners.
I'd give them about another foot to 18" lead at 200 yds when they are running hard and see what happens. Keep the muzzle swinging as you squeeze the trigger. Stopping the gun equates to shooting behind them.
Where I shoot, without a suppressor they run away from me. With a suppressor they all run random directions because they hear the bullet impact more than the muzzle blast and wonder where it came from.
With some running full tilt left, some full tilt right, some at me and, some away the challenge is different but, I also have more time to take more shots since they don't all hit cover or get out of range (or in front of a bad backstop like cattle in the next pasture, a house, or public road, or ...) at the same time.
